The invention relates to end doors for railway cars, in particularly to radial end doors of the type used in railcars for transportation of automotive vehicles.
A radial end door of the type to which the invention relates is shown and described in U.S. Pat. No. 5,765,486, the disclosure of which is incorporated herein by reference. As described therein, each of the end doors is supported by inner and outer rollers at the bottom of the door. The rollers travel on an arcuate track extending along the floor of the car and out along the outside of the side wall. The track is curved substantially uniformly about a predetermined radius. A pair of lock pins are provided for engagement with bores on upper and lower decks of the railcar. Each lock pin is associated with a first bore corresponding to the open position of the door, and a second bore corresponding to the closed position of the door. This type of locking arrangement is illustrated in, e.g., U.S. Pat. No. 5,829,360, the disclosure of which is incorporated herein by reference.
While the door described and shown in U.S. Pat. No. 5,765,486 is believed to provide significant advantages over doors that have been used in the past, there is still room for improvement. The door has an outer portion that extends generally upward above the arcuate track when the door is in closed position, and has a generally planar inner portion extending inward therefrom. When the door is slammed, or closed with excessive force, it is possible that the door may rotate or rock inward to some extent, such that the top of the inner edge of the door moves beyond its closed position, and the lock on the upper deck may not properly engage. The door may jam in this position, leading to considerable difficulty in subsequently opening the door. Furthermore, even when the door is closed with the locks properly engaged, the door may nevertheless be susceptible to rocking about the inner roller, with the outer roller lifting slightly off the track. The inner roller is positioned at the inner extremity of the arcuate outer portion of the door, and thus it cannot be moved any further inward while still sharing a track with the outer roller without changing the configuration of the door.
In addressing the above problems, any solution should avoid unduly increasing the force required to open the door. It is desirable that the required opening force not exceed about 40 lbs.
It is a general object of the invention to solve the above mentioned problems without adversely effecting the load carrying capacity of the car, i.e., without reducing longitudinal clearance near the end of the car, while maintaining the basic, successful, proven configuration and geometry of the door arrangement described in U.S. Pat. No. 5,765,486.
The invention comprises a radial end door that includes a door mounted nose support on the inner portion of the door. The door mounted nose support preferably is unsupported by the railcar body when the door is open, but supported by the railcar body when the door is closed. The support preferably can be added as a retrofit or upgrade to the existing door, without altering the basic configuration, geometry or operational characteristics of the door, except to improve the performance of the door by addressing the problems discussed above. The support may be installed after installation of the door on the railcar, with a shim inserted on the railcar floor to assist in determining the proper elevation of the support.
In addition to the door mounted support, there is preferably provided a floor mounted support that engages the door mounted support when the door is in closed position.
The door mounted support preferably comprises a roller assembly, and the floor mounted support preferably comprises a wear bar having a ramp portion. As the door is moved toward its fully closed position, the door mounted support engages the ramp portion and is lifted slightly to increase load on the outer roller, and to assist in smoothly stopping the door at its closed position, even when the door is slammed or otherwise subjected to excessive closing force.
The door-mounted roller preferably is trackless, i.e., unlike the other rollers on the door, it does not travel on a track, but rather only performs a supporting function when the door is in or near its closed position.
The door-mounted nose support preferably is economical, lightweight and easily installed, and capable of interfitting with existing radial doors to be welded thereto. To this end, the door-mounted nose support preferably is composed of only a small number of parts, e.g., a roller assembly, a roller shaft supporting the roller assembly, and a housing supporting the roller shaft. In one embodiment, the housing includes a mounting plate having first and second flanges which are angled to lie flat against surfaces of the radial door, and which are welded thereto, and a roller-supporting intermediate portion between the flanges, suitably angled relative to the flanges to support the roller obliquely relative to the inner portion to the door so that its axis is substantially perpendicular to its direction of travel as the door reaches its closed position. The preferred housing further includes a compact, removable roller assembly that avoids interference with loading ramp clearances and motor vehicle clearances.
The roller assembly is preferably attached to the mounting bracket by a plurality of fasteners, at least some of which are disposed between the roller and the mounting bracket. This enables the roller assembly to removably attached to the mounting bracket without requiring the roller assembly to be much wider than the roller itself. The roller assembly thus requires less lateral clearance than conventional roller assemblies having outwardly extending flanges or ears.
In the preferred roller assembly, the roller is positioned between a C-shaped or channel-shaped roller support and a flat cover plate welded thereto. The roller support is removably secured to the mounting plate by fasteners such as bolts, and the roller shaft is supported by the roller support and cover plate.
The improvement preferably prevents rocking of the door, increases stability of the door, and increases loading on the outer roller when the door is in closed position. The door has sufficient strength and durability to withstand a period of several years of commercial rail service in transporting automotive vehicles with minimal maintenance. The door mounted support may be removed and replaced when necessary without undue difficulty.